In which symbotic relationship does one organism benefit while the other organism is harmed?

What can be said about farmers in highly developed countries? a) they have little or no negative impact on the environment. b) they practice subsistence agriculture. c) they are able to incorporate polyculture into their farming practices. d) they utilize organic farming techniques on a regular basis. e) they rely on large amounts of energy from fossil fuels.

What is the most appropriate method of gaining weight (muscle mass)

What element is able to combine with itself and hydrogen to form large molecules ?